Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/IRICEN1/themes/fisubsilversh/theme.php:138) in /var/www/html/IRICEN1/includes/sessions.php on line 249
Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/IRICEN1/themes/fisubsilversh/theme.php:138) in /var/www/html/IRICEN1/includes/sessions.php on line 250

Indian Railways Institute of Civil Engineering: Forums

Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/IRICEN1/themes/fisubsilversh/theme.php:138) in /var/www/html/IRICEN1/includes/page_header.php on line 477
Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/IRICEN1/themes/fisubsilversh/theme.php:138) in /var/www/html/IRICEN1/includes/page_header.php on line 479
Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/IRICEN1/themes/fisubsilversh/theme.php:138) in /var/www/html/IRICEN1/includes/page_header.php on line 480

Railway board's latest circular on procurement of ballast says that supply of ballast to be taken as per P.WAY. manual in case of cess supply works and deficiencies to be made up with DMT.In P.WAY.manual ,qty. of ballast has been given for single line sections only i.e. there is no mention of double/multiple line sections.In case of double/multiple line const., single slope of 1 in 30 is to be given to the underneath formation as per RDSO guidelines for earthwork resulting which actual requirement of ballast works out to be more than the given qty. as per P.WAY. manual for maintaining minimum ballast cushion under the rail seat on existing track side. The difference in qty. is mainly due to difference of formation slopes in both the cases because ballast qty. gets compensated due to formation of peak in subgrade(both sides slope) in case of single line section where as qty.goes on increasing due to one sided/single slope in case of double/multiple line section.
More ballast deficiency is observed in later case as compared to former and becomes difficult to keep ballast profile as per manual before opening of line.
My questions are
1) should be approach for issuance of correction slip of P.WAY. manual to cover the qty. of double/multiple lines also in view of above.explaination?
2)what should be the criteria for estimation of ballast for cess supply contracts for double/multiple line section as P.WAY. manual is silent in this case ?

The extra quantity of ballast involved in double or multiple line can be calculated based on the features given for single track in IRPWM and nobody can object to the additional quantity.

I agree that the profile for single track should be for formation slope to one side only ie towards cess side where additional track is not likely to come up in case of doubling. However it is very difficult to predict where the additional lines are expected to come up during doubling. In case it comes on the wrong side where it was not predicted, then instead of having formation slopes on either side for double track, we may have to go for slope in single direction, least track drainage will get affected and that will cause more wastage of ballast. That is why double side slope is given for single line track so the future track where ever it comes can be continued on same slope.

For the given situation what ever is found economical without affecting the track drainage can be adopted even if it means changing the formation slope of existing track though cutting the consolidated formation is generally not preferred. However full ballast cushion just below the rail seat should be available as shown in IRPWM. If providing a central drain is economical, than other options then that can be done

The triangular wedge portion,which increases the quantity in
doubling, works out to 0.43cu.m/m and consequent decrease in
qty in single line works out to 0.21cu.m/m,summing up to
0.64cu.m/m ie,>30% extra.The Qty is quite considerable.
Also decrease in Qty of 0.31cu.m/m =15% is worked out,with
the change of sleeper density from 1540 to 1660/km,which is
lost sight off in the P-Way manual.
Matter got to be reviewed